MIL-HDBK-793

Abstract

Nondestructive testing is the testing of materials or structures without causing failure of the item being tested. There are three acronyms that are in general usage: nondestructive testing (NDT), nondestructive evaluation (NDE), and nondestructive inspection (NDI) (or nondestructive investigation (NDI)). These terms are used by various authors to describe the same basic types of testing. NDT is the more general term, ND1 (inspection) is preferred by the quality control engineer, and NDE and ND1 (investigation) are preferred by the research scientist. <br>This handbook briefly describes the materials of interest, namely, the organic or polymeric matrix-fiberreinforced composites. The various nondestructive techniques available are described in a manner that o&#252;tlines the techniques. However, this handbook is not intended for use as an operator's manual for the techniques discussed. <br>This handbook covers the testing that can and should be carried out on (1) incoming materials, such as prepregs, resins, and fibers, to help build quality assurance into the subsequent parts, (2) the types of tests that can be used during fabrication and on the final product, and (3) in-service use of NDT. In-service use of NDT covers the problems related to in-service testing in evaluating such properties as reliability, durability, and life expectancy of a fiber-reinforced composite by nondestructive means. <br>Further, an attempt will be made to alert the reader to new and promising techniques that are being developed. <br><strong>PURPOSE</strong> <br>The purpose of this handbook is to educate the reader as to the nature of nondestructive testing of fiber-reinforced polymeric materials. Metal-matrix composite materials are another subject and will not be addressed here. The intent is to advise the reader about the various techniques available for use during the inspection of the raw materials and incoming component materials, for inspection during fabrication, and for final inspection and in-service monitoring to detect damaged and/ or degraded structures.